Attaching method for slide fastener elements



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ATTACHING METHOD FOR SLIDE FASTENER ELEMENTS Filed July 11, 1960 4 Sheets-Sheet 3 1964 A. STEINGRUEBNER 3,158,118

ATTACHING METHOD FOR SLIDE FASTENER ELEMENTS Filed July.ll. 1960 INVENTOR: )Hmwa ITE/A/6Rl BA/ER *GENT 4 Sheets-Sheet 4 v United States Patent Ofiiice 3,158,118 Patented Nov. 24, 1964 ATTACHING BETH- D FGR SLEDE FASTENER ELEMENTS Arthur teingrnebner, Bonn, Germany, nssignor to Wahl lire-titers, New York, N .Y., a partnership Filed July 11, 1961), S03. No. 42,635 @iairns priority, application Germany July 14, 1%?

5 Claims. ((Ii. 112-265) This invention relates to the manufacture of slide fasteners, and more particularly to a method and device for producing a slide fastener chain having a continuous elongated carrier, such as a tape, and a plurality of Iongitudinally spaced rows of interlocking elements secured to the carrier.

The preferred type of slide fastener for many applications consists of two lengths of elongated carriers, such as tapes of .textile material, arranged side by side and connected by two rows of interlocked elements respectively secured to the carriers. The element rows are shorter than the lengths of tape to which they are secured so as to provide free tape ends which facilitate sewing of the slide fastener into a garment and the like.

Fastener chain having on each tape successive interlocking elements which are integral portions of a single piece of material, such as a suitably shaped metal wire or plastic filament has found wide acceptance recently. It is common practice to shape the wire or filament into a row of interlocking elements and then to attach the row of elements to a tape by sewing on a suitably adapted sewing machine. In the usual modified sewing machine employed, continuous strands of interlocking elements are sewn to continuous lengths of carriers to produce a continuous chain from which individual fastener lengths are then cut.

If free tape ends are desired, it is necessary to remove the two terminal portions of the row of slide fastener elements from the cut chain length. This additional removal operation is costly in itself and necessitates the loss of substantial amounts of fastener element material. In a slide fastener having a 7" row of fastener elements in the finished condition and 1" free ends at either end, the loss of fastener element material amounts to 22% of the total material employed. The cut-away fastener elements are practically useless and Without value as scrap material.

A primary object of this invention is to improve the manufacture of slide fastener chain having tree tape ends at each fastener end.

Another object is the provision of a method, and of a device for performing the method, which avoids the emoval operation of fastener elements for the purpose of making fastener lengths with free tape ends.

An adidtional object is to avoid the material losses inherent in the removal operation referred to above.

With these and other objects in view, the invention provides a method of producing slide fastener chain having acontinuous carrier, such as a textile tape, and a plurality of longitudinally spaced rows of interlocking elements secured to the carrier. When the slide fastener chain of the invention is cut transversely in the gap formed on the carrier tape between successive spaced rows, there is obtained a length of chain having free tape ends. This method is applied to two interlocked chains produced simultaneously in a single operation.

In its more specific aspects, the method of the invention involves passing two continuous lengths of slide fastener carrier or tape through a mounting station, such as the sewing area of a sewing machine, and feeding two continuous strands of interlocked fastener elements in a direction toward the same mounting station. As

the strands of fastener elements are being fed toward the mounting station, each is cut into a forward portion adjacent the mounting station, and a rearward portion remote from the station. The feeding movement of the rearward portion is arrested while the movement of the forward portion toward the station continues, and the forward portion is being mounted on a respective carrier while the rearward portion is temporarily arrested. A gap between a forward and a rearward row of fastener elements is thus formed in the continuous fastener emerging from the mounting station, and a transverse cut made across the gap in a manner which is conventional in this industry will result in fastener lengths having free tape ends.

To perform the method of the invention, I provide a device which includes a sewing station and separate feeding means for .continuousuly feeding a continuous carrier toward the sewing station, and for feeding strands of slide fastener elements to the sewing station along a predetermined path. The fastener clement feeding means of the invention includes a feed dog arranged at a distance from the sewing station, and a cutter between the feed dog and the sewing station. The feed dog can be moved into the path of the fastener elements for engagement therewith, and hence along the path to advance the elements toward the sewing station, and can then be withdrawn. The cutter also is moved into and out of the path of the elements to cut a continuous strand of fastener elements into discrete lengths.

Other features and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawing in which like reference numerals designate like parts throughout the figures thereof, and wherein:

FIG. 1 is a side elevational view of a double-needle chain stitch sewing machine modified for performing the method of the invention, with parts of the sewing machine broken away to show operating elements of the device of the invention;

FIG. 2 shows a portion of the apparatus of FIG. 1 in front-elevational sectional view on line IIII;

FIG. 3 is a fragmentary, partially sectional view of the apparatus of FIG. 1, the section being taken on line Iii-III of FIG. 2;

FIG. 4 is a perspective view of details of the app-aratus of FIG. 1 with portions of the apparatus removed to reveal the operating elements of the invention; and

FIG. 5 shows the apparatus of FIG. 4 in a different operating position.

Referring now to the drawing in detail, and initially to FIG. 1, there is shown a double-needle chain stitch sewing machine of generally conventional type and illustrated only to the extent necessary for explaining the present invention. Although many internal working parts of the sewing machine have not been shown explicitly, it will be understood that the sewing machine includes a source of power for actuating sewing movement, and a power transmission train for transmitting motion to the several working parts in a synchronized manner.

The sewing machine has a head 1 which includes a horizontally extending arm 2 on the free end of which a needle bar 3 is mounted for reciprocating vertical movement. equipped with a needle holder 4 to which two needles 5 and 6 are fastened in side by side arrangement for producing two parallel seams.

As is customary in chain stitch sewing machines, two threads are fed to each needle in the direction of the arrow 7. The needles 5, 6 receive respective first threads 8, 9 from tension discs 1%), 11 to which they are led by The bottom end of the needle bar 3 is.

thread guides 12, 13 and eyes 14-, 15 from respective supply spools 16, 17. Second threads 18, 19 are passed to the needles 5, 6 from a thread take-up 2t} and a common tension disc 21. The second threads are drawn from respective thread spools 28, 2? through thread guides 24, 26, 27 and over idler guide pulleys 22, 23. The eyes 14, 15 and the spools 16, 17, 28 and 29 are mounted on spool pins 36), 31 in the usual manner.

The arm 2 of the sewing machine head 1 is equipped with two integral brackets 32, 33 on which storage drums 34 and 35 for slide fastener tapes 37 and 36 are rotatable. The tapes 36, 37 are led downwardly from the spools 34, 35 and through a slot between a throat plate 33 and a bed plate 39 of the sewing machine. They leave the sewing area with fastener elements 43 attached thereto to form a finished chain which is then delivered from the sewing machine by a pair of pinch rolls of which only the upper roll 91 is visible in FIG. 1.

The fastener elements 23 are drawn toward the sewing area from a storage drum 4b which is rotatable about a horizontal axis between two brackets 41 and 42 mounted on the base housing of the head 1. The fastener elements 43 form two interlocked continuous strands.

The base housing holds the stitch forming elements which cooperate with the needles 5, 6 to form chain stitches which attach the slide fastener elements 43 to the tapes 36, 37. Since these stitch forming elements are well known in themselves, they have been omitted from the drawing, and a more detailed explanation thereof is not necessary for an understanding of this invention.

A portion of the sewing machine base has been broken away to show elements of the motion transmitting train which actuates movement of the upper pinch roll 91 and of other parts of the mechanism. A sprocket 79 is connected to the main drive of the sewing machine by means of the shaft 35 for continuous rotation. As will be shown in more detail hereinafter, a chain 87 transmits movement of the sprocket 79 to a sprocket 8%; which is fixedly fastened on a common shaft 39 with the pinch roll 91. The shaft 39 is supported in a pillow block 90 on the bed of the head 1.

The shaft 85' has an integral crank shaft extension 77 journaled in a standard 78 in the base housing of the sewing head 1. A long crank pin 75 is eccentrically mounted on the shaft 77 by means of a crank web 76 for actuating intermittent feeding of slide fastener elements toward the sewing area as will be more readily apparent hereinbelow.

FIG. 2 shows the base housing of the sewing machine 1 in front elevational section to reveal the mechanism for feeding strands of slide fastener elements 43 to the sewing area. The throat plate 33 and bed plate 39 are mounted superimposed on the cover 4-7 of the housing and a continuous strand of two interlocked rows of slide fastener elements 4-3 is being drawn toward the sewing area from the storage drum at) which is seen to be mounted on the sidewall 53 of the housing by means of the bracket 42. The sewing area is indicated by vertical openings 44 and 45 in the throat plate 38 and the bed plate 39 respectively through which the needles 5 and 6 move up and down in the usual manner.

The fastener elements 43 are guided toward the sewing area by a guide groove as in the bed plate 39 which extends between the drum 4%) and the openings 44, 45. The cover 47 has a recess 48 at the bottom of the groove 46 which accommodates a feed dog 49 having teeth which can be moved up and down through the recess 48 into and out of the groove 46, and longitudinally of the groove in a direction toward the sewing area. The teeth are adapted to engage the elements 4-3.

The feed dog 4-? is mounted on a link 50, one end of which is rotatably secured to the crank pin 7 5 (see FIG. 1) for movement in a circular path parallel to the Plane of FIG. 2. The other end of the link 54) is hinged by means of a pin 51 to a plunger 53. The pin 51 engages a longitudinal slot 52 in the plunger 53 to permit longitudinal movement of the link 59 relative to the plunger 53. The plunger 53 is guided for free vertical movement in the base housing of the head 1 by a guide cylinder 54 which is fixedly secured to the housing bottom 67.

The plunger 53 carries a laterally projecting cam follower 55 which cooperates with a cam disc 56 to actuate vertical reciprocating movement of the plunger 53. The cam disc 56 is rotated by a sprocket S7 to which it is fixedly fastened and which is rotatably mounted on the housing sidewall 58.

A pin 64 on the plunger 53 transmits the movement of the latter to one end of a lever 65. The center of the lever is supported on a column 68 by means of a pin 66 which passes through an elongated opening in the lever 65. The other end of the lever 65 is formed with a longitudinally elongated opening for passage of a pin 69 on a cutting block 78. The block 74) carries a cutting blade 71 and is slidably retained in a guide channel 72 integral with the base housing cover 4-7 and having its orifice in the groove 46.

The synchronized drive arrangement for the feed dog 49 and the cutting blade 71 is best seen from FIG. 3 which shows the relevant portion of the device illustrated in FIG. 2 in plan View. The sprocket 57 is intermittently rotated by a chain 59 which is trained over an idler 57' adjacent the sprocket 57 and a sprocket 6t) rotatably mounted on the sidewall 53 of the base housing. The sprocket 65} rotates continuously and is driven from the main drive of the sewing machine by a pair of bevel gears 51 driven by a shaft 62 which is supported in the housing by a pillow block 63. The continuous movement of the sprocket 69 is imparted to the chain 53, but is transmitted only intermittently to the sprocket 57 by driving dogs 94 on the chain 5% which extend radially outward from the idler 57 when passing over the latter and engage the teeth of the sprocket 57. While only a single dog 94 has been shown in FIG. 3 for the sake of clarity, it will be understood that the chain may carry as many spaced dogs 94 as are required to impart the desired movement to the plunger 53, to the teeth 73 of the feed dog 49, and to the cutting blade 71.

The elements transmitting the movement of the shaft 85 to the pinch roll 91 are seen more clearly in FIG. 3 than in FIG. 1. A chain is trained over the sprocket 79 on the shaft and over a sprocket 81 which is rotatably mounted on the base housing by means of two brackets 82, 83 on a shaft 84 to which the sprocket S1 and a sprocket 86 are fixedly fastened. The sprocket 86 which is obscured in FIG. 1 drives the chain 87, and thus the pinch roll 91. The lower pinch roll 92 is driven by friction with the finished fastener chain 93 as it passes between the pinch rolls as seen in FIG. 2.

A locking arm 74 is attached to the bed plate 39 for cooperation with the teeth 73 of the feed dog 49 as is seen in FIG. 5. The teeth were omitted from FIG. 4 for the sake of clarity.

The operation of the aforedescribed device is best understood from FIGS. 4 and 5 which show only the essential operating elements of the device in two different positions.

As the needles 5, 6 on the needle holder 4 reciprocably move into and out of the openings 44- inthe throat plate 38, they sew each of the two rows of fastener elements which constitute the continuous strand 43 to one of the tapes 36 and 37. The tapes with the elements attached emerge from the sewing station as a piece of finished fastener chain 93 the two halves of which are in interlocking engagement. The finished fastener chain 93 is drawn from the sewing station by the cooperating pinch rolls 91 and 92 which continuously rotate in the directions of the arrows.

The movement of the tapes 36 and 37 through the sewing station thus is continuous. The fastener ele ments 43 are moved through the sewing station because of the fact that a forward portion of the elements is sewn to the tapes and must move with the latter. Feeding of the elements toward the sewing station is controlled by the feed dog 49.

The feed dog is fixedly mounted on the link 50 the two ends of which respectively partake of the continuous movement of the crank pin 75 and the intermittent movement of the cam follower 55. As seen in FIG. 4, the cam follower 55 travels over a cam portion of the disc 56 which raises the cam follower to its highest position, whereby the link 50 raises the feed dog 49 into its operative position. Because of the circular movement imparted to the corresponding end of the link 50 by the crank pin 75, the teeth '73 of the feed dog 49 travel in a circular path of smaller radius in a clockwise direction as viewed in FIG. 4. They move from a position in which they are out of engagement with the elements 43 and substantially withdrawn from the groove 46 which defines the path of the elements, upward into engagement with the elements in the groove 46, and hence forward toward the sewing station. The teeth 73 are then withdrawn downward from the fastener elements 43 and moved back toward the starting position while out of range of the fastener elements. The eccentricity of the crank pin '75, and the dimensions of the link 59 and of the elements cooperating with it are selected in such a manner that the fastener elements 43 are fed toward the sewing station for combination with the tapes 36 and 37 at the desired ratio for proper spacing of the elements on the tape. The resilient locking arm 74 urges the fastener elements 43 against the bottom of the groove 46 when the feed dog 49 is withdrawn.

Engagement of the sprocket 57 by one of the drive dogs 94 on the chain 59 causes angular displacement of the cam disc 56. The cam follower 55 drops from the position shown in FIG. 4 to that seen in FIG. 5. The feed dog 49 is thereby withdrawn into a position in which the teeth 73 cannot engage the fastener elements 43 during movement of the crank pin '75. Feeding of the strand of slide fastener elements toward the sewing station is stopped, and the portion of the strand of elements above the feed dog 49 is clamped to the bottom of the groove 46 by the arm 74.

The sudden downward movement of the cam follower 55 and of the connected arm of the lever 65 causes the I other arm of the lever to be raised suddenly, and the cutting blade 71 severs the strand of fastener elements intermediate the arm '74 and the sewing station. The severed forward end is drawn into the sewing station and sewn to the tapes there. The rearward portion is immobilized until the cam follower 55 is raised again to the position shown in FIG. 4 by the next drive dog 94 passing over the sprocket 57, whereupon forward feeding of the fastener elements toward the sewing station is resumed.

Since tape feed and sewing proceed continuously, there emerges from the pinch rolls from time to time a length of fastener chain the tapes of which do not carry fastener elements. When the continuous chain is then cut across these lengths, individual pieces of fastener chain with free tape ends are obtained. The length of the chain portions having fastener elements mounted thereon, and the length of the gap between these chain portions on which no elements are sewn is determined by the spacing of the drive dogs 94 on the chain 59, and may be altered simply either by changing the positions of the dogs 94 on the chain 59, or by interchanging several chains having differently spaced dogs.

It should be understood, of course, that the foregoing disclosure relates to only a preferred embodiment of the invention, and that it is intended to cover all changes and modifications of the example of the invention herein chosen for the purposes of the disclosure which do not constitute departures from the spirit and scope of the invention set forth in the appended claims.

What I claim and desire to be protected by Letters Patent of the United States is:

1. A method of producing slide fastener 'chain including two continuous elongated carriers and a plurality of paired rows of interlocked fastener elements respectively secured to said continuous carriers, said paired rows being longitudinally spaced from each other, comprising the steps of continuously passing said carriers through a sewing station; feeding two continuous interlocked strands of said fastener elements in a direction toward said sewing station, each strand consisting of an integral substantially filament shaped member; cutting said two continuous strands into interlocked respective forward portions adjacent said sewing station, and interlocked respective rearward portions remote from said station; arresting feeding movement of said rearward portions; and simultaneously continuing feeding movement of said interlocked forward portions toward said sewing station for sewing to respective ones of said carriers at said station.

2. A method as set forth in claim 1, which further comprises simultaneously passing two seams of sewing stitches through respective ones of said two interlocked strands of fastener elements and of said carriers at said sewing station to sew each carrier to a respective strand while said strands are interlocked.

3. A method of producing slide fastener chain including two continuous elongated carriers and two interlocked strands of fastener elements respectively secured to said continuous carriers, which comprises longitudinally feeding to a sewing station two continuous elongated carriers and two continuous interlocked strands of fastener elements, each strand consisting of an integral substantially filament shaped member, respective portions of said member constituting said elements; and sewing the elements of said strands to said carriers respectively at said sewing station while the elements of said strands are mutually interlocked.

4. A method as set forth in claim 3, which further comprises, discharging said carriers with the interlocked strands of fastener elements respectively sewn thereto from said sewing station.

5. A method as set forth in claim 3, wherein the elements of said strands are sewn to the respective carriers by simultaneously passing two seams of sewing stitches through respective ones of said two interlocked strands of fastener elements and of said carriers to sew each carrier to a respective strand while said elements are interlocked.

References Cited in the file of this patent UNITED STATES PATENTS 2,327,983 Paux Aug. 31, 1943' 2,369,026 Dasher u, Feb. 6, 1945 2,730,973 Rohrlick Ian. 17, 1956 2,822,770 Schwartz Feb. 11, 1958 2,857,866 Porepp Oct. 28, 1958 3,057,031 Wahl Oct. 9, 1962 

3. A METHOD OF PRODUCING SLIDE FASTENER CHAIN INCLUDING TWO CONTINUOUS ELONGATED CARRIERS AND TWO INTERLOCKED STRANDS OF FASTENER ELEMENTS RESPECTIVELY SECURED TO SAID CONTINUOUS CARRIERS, WHICH COMPRISES LONGITUDINALLY FEEDING TO A SEWING STATION TWO CONTINUOUS ELONGATED CARRIERS AND TWO CONTINUOUS INTERLOCKED STRANDS OF FASTENER ELEMENTS, EACH STRAND CONSISTING OF AN INTEGRAL SUBSTANTIALLY FILAMENT SHAPED MEMBER, RESPECTIVE PORTIONS OF SAID MEMBER CONSTITUTING SAID ELEMENTS; AND SEWING THE ELEMENTS OF SAID STRANDS TO SAID CARRIERS RESPECTIVELY AT SAID SEWING STATION WHILE THE ELEMENTS OF SAID STRANDS ARE MUTUALLY INTERLOCKED. 